Horizontal openings often use connected slats as a covering. When opened, the interconnected slats can either roll onto a shaft or slide horizontally into a receiving space.
Access openings in warehouse, manufacturing and industrial settings are often secured by overhead (vertically traveling) closures. One popular type of overhead closure is a coiling closure, for example, slatted doors, such as rolling steel doors, which move in a generally vertical path coiling above the opening as the door is opened. Because overhead coiling closures have many fewer parts than other door types with less risk for damage and inoperability, they often make a better solution for facilities that cannot afford opening downtime.
An overhead coiling closure is either provided with a powered operator to power the door to an open or closed position or it is manually opened and closed with, for example, a looped chain or crank. A shaft is horizontally mounted above the access opening to wind or unwind the coiling closure. The coiling shaft and operator (if present) are usually covered by a hood.
Another popular type of overhead closure is a sectional overhead door. Sectional overhead doors are manufactured from horizontally hinged panels that roll into an overhead position on tracks, usually spring-assisted. Each panel of the sectional overhead door has its own connection to the door track. This increases reliability and robustness compared to monolithic doors which have only a couple of track connections for the whole panel.
A sectional overhead door may be provided with a powered operator (motor) operatively connected to a panel to power the door to an open or closed position, or it may be manually opened and closed, for example with a handle.
Horizontal doors are prone to displacement forces when objects fall upon them. Likewise, when overhead closures are installed in high traffic areas, for example, shipping and receiving areas the door can get struck by, for example, a fork lift transporting cargo and/or by the cargo being trucked by the lift. When struck, the door will bow and if the striking force is great enough the door roller will dislodge from its track. Once the door becomes damaged the closure may become non-operational with resultant access opening downtime.
Accordingly, there is still a continuing need for improved door protection designs. The present invention fulfills this need and further provides related advantages.